ALMA observations of massive clouds in the Central Molecular Zone

• Verfasst von: Lu, Xing [VerfasserIn]
• Verfasst von: Cheng, Yu [VerfasserIn]
• Verfasst von: Ginsburg, Adam [VerfasserIn]
• Verfasst von: Longmore, Steven N. [VerfasserIn]
• Verfasst von: Kruijssen, Diederik [VerfasserIn]
• Verfasst von: Battersby, Cara [VerfasserIn]
• Verfasst von: Zhang, Qizhou [VerfasserIn]
• Verfasst von: Walker, Daniel L. [VerfasserIn]
• Titel: ALMA observations of massive clouds in the Central Molecular Zone
• Titelzusatz: jeans fragmentation and cluster formation
• Verf.angabe: Xing Lu, Yu Cheng, Adam Ginsburg, Steven N. Longmore, J. M. Diederik Kruijssen, Cara Battersby, Qizhou Zhang, Daniel L. Walker
• E-Jahr: 2020
• Jahr: 2020 May 7
• Umfang: 11 S.
• Teil: volume:894
• Teil: year:2020
• Teil: number:2
• Teil: extent:11
• Fussnoten: Gesehen am 02.07.2020
• Titel Quelle: Enthalten in: The astrophysical journal / 2
• Ort Quelle: London : Institute of Physics Publ., 1995
• Jahr Quelle: 2020
• Band/Heft Quelle: 894(2020,2) Artikel-Nummer L14, 11 Seiten
• ISSN Quelle: 2041-8213
• DOI: doi:10.3847/2041-8213/ab8b65
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1703269047

Abstract

We report Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 continuum observations of 2000 au resolution toward four massive molecular clouds in the Central Molecular Zone of the Galaxy. To study gas fragmentation, we use the dendrogram method to identify cores as traced by the dust continuum emission. The four clouds exhibit different fragmentation states at the observed resolution despite having similar masses at the cloud scale (∼1-5 pc). Assuming a constant dust temperature of 20 K, we construct core mass functions of the clouds and find a slightly top-heavy shape as compared to the canonical initial mass function, but we note several significant uncertainties that may affect this result. The characteristic spatial separation between the cores as identified by the minimum spanning tree method, ∼104 au, and the characteristic core mass, 1-7 , are consistent with predictions of thermal Jeans fragmentation. The three clouds showing fragmentation may be forming OB associations (stellar mass ∼103 ). None of the four clouds under investigation seem to be currently able to form massive star clusters like the Arches and the Quintuplet (≳104 ), but they may form such clusters by further gas accretion onto the cores.